PowerShell Requires Chilkat v11.7.0+

QR Code Error Correction Levels

See more QR Code Examples

Demonstrates the four QR error-correction levels. L, M, Q and H allow a reader to recover the data when about 7%, 15%, 25% and 30% of the symbol is damaged or covered. More error correction leaves less room for data, so the same text needs a larger symbol at a higher level. The default is M. The example also shows boostErrorCorrection, which raises the level for free when the chosen version has room to spare. PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

$fmt = New-Object Chilkat.Formats
$json = New-Object Chilkat.JsonObject
$jsonOut = New-Object Chilkat.JsonObject
$json.UpdateString("payload.text","https://www.chilkatsoft.com/barcode_overview.asp")

#  Encode the same text at each level.
$levels = New-Object Chilkat.JsonArray
$levels.Load("[`"L`",`"M`",`"Q`",`"H`"]")

for ($i = 0; $i -le 3; $i++) {
    $json.UpdateString("encoding.qr.errorCorrection",$levels.StringAt($i))
    $success = $fmt.QrCode("generate",$json,$jsonOut)
    if ($success -eq $false) {
        $($fmt.LastErrorText)
        exit
    }

    $("level " + $levels.StringAt($i) + ": version " + $jsonOut.IntOf("symbols[0].selectedEncoding.version") + ", " + $jsonOut.IntOf("symbols[0].dimensions.modulesWide")
         + " modules wide")
}

#  The four symbols.  They hold the same text, and the higher the level, the larger the symbol:

#  

#  A symbol often has room left over.  boostErrorCorrection uses it: the level is raised
#  as far as the same version allows, so the symbol is no larger but is more robust.
$json2 = New-Object Chilkat.JsonObject
$json2.UpdateString("payload.text","https://chilkatsoft.com")
$json2.UpdateString("encoding.qr.errorCorrection","L")
$success = $fmt.QrCode("generate",$json2,$jsonOut)
if ($success -eq $false) {
    $($fmt.LastErrorText)
    exit
}

$("level L requested: version " + $jsonOut.IntOf("symbols[0].selectedEncoding.version") + ", level " + $jsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection"))

$json2.UpdateBool("encoding.qr.boostErrorCorrection",$true)
$success = $fmt.QrCode("generate",$json2,$jsonOut)
if ($success -eq $false) {
    $($fmt.LastErrorText)
    exit
}

$("level L with boost: version " + $jsonOut.IntOf("symbols[0].selectedEncoding.version") + ", level " + $jsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection"))

#  Level L, and level M reached by the boost.  The two symbols are the same size:

#  

#  Sample output:

#  level L: version 3, 29 modules wide
#  level M: version 4, 33 modules wide
#  level Q: version 5, 37 modules wide
#  level H: version 6, 41 modules wide
#  level L requested: version 2, level L
#  level L with boost: version 2, level M